Light emitting assembly and method of transfer printing a micro-LED

A method of manufacturing and transfer printing micro-LEDs to a semiconductor packaging board comprising the steps of:

• (a) forming on a growth substrate a semiconductor stack that includes a first-type semiconductor layer, a second-type semiconductor layer, and an active layer located between the first-type semiconductor layer and the second-type semiconductor layer;
• (b) removing partially the semiconductor stack to form an array of semiconductor structures each having a first mesa surface and a second mesa surface that are respectively defined by the first-type semiconductor layer and the second-type semiconductor layer, and forming a first electrode and a second electrode on the first mesa and the second mesa, respectively;
• (c) forming a first insulating dielectric layer to cover the first mesa surface and the second mesa surface of each of the semiconductor structures;
• (d) covering the first insulating dielectric layer with a sacrificial layer, and bonding the sacrificial layer to a supporting substrate, wherein the sacrificial layer forms a removable bonding connection between each of the semiconductor structures and the supporting substrate;
• (e) removing a whole of the growth substrate and part of the first type semiconductor layer so that spacings are created between the semiconductor structures;
• (f) etching away the sacrificial layer to disconnect each of the semiconductor structures from the supporting substrate, followed by forming part of the first insulating dielectric layer into bridging arms such that each of the semiconductor structures has at least two of the bridging arms, wherein the bridging arms are shaped through a patterned photomask, the bridging arms are thinned using a dry etching process so that the bridging arms have a thickness that is less than a thickness of a first mesa covering portion of the first insulating dielectric layer that covers the first mesa surfaces, and the array of the semiconductor structures are formed into an array of separable independent micro LEDs;
• (g) removing the micro-LEDs from the supporting substrate, and transfer printing the micro-LEDs to a packaging substrate.